While I was living in Madrid I went there for countless times because it's so cheap and tasty. Definitely my favourite place when it comes to price and taste.
Still dreaming about the food I ate there, specifically the cakes.

Cheap and nice junk food! Bocadillos, burguers, Spanish omelette (scary, so similar to egg version) and many other typical Spanish vegan versions food, Estrella Galicia ;) and good environment! Only problem is that is always so busy and you might have to wait a bit for a table.

Great place to eat some copycats of "omnivores" food. Most of the food is frozen but you're not coming here for a classy dinner. Try vegan calamari, chorizo, bacon and seitan sandwiches, any of their many hamburgers and several tapas, but the best choice is to order the homemade spanish omelette, which is delicious.

Probably the cheapest place to eat vegan in Madrid and sometimes you can't even finish your plate.

I was very excited to go to B13 considering the reviews and the fact that the first Sunday evening when I tried, it was completely full. But finally, I was a bit disappointed by the food. You have a large choice of vegan junk food (and more), everything looks appealing but when you get it, it is rather simple and not very original in terms of taste. You can do most of their menu at home with products bought in a vegan shop. The very good point is that it is very cheap, and quickly served. If it was organized as a bar, it could be a nice place to have a drink with friends. But the current interior layout, because the restaurant is very small, does not let the possibility to create a nice bar atmosphere where you wanna stay. Ideal for a quick and cheap bite of vegan junk food, but nothing more.

This place is just next to Gran Vía, just in the centre of Madrid. The atmosphere was quite nice, full of friendly Spanish pals. Food wasn't so tasty but wasnt awful either. The very good thing is that you can eat here by almost half of the price of other Madrid vegan restaurants. If you want to fill your empty stomach at a very affordable price, this is your place. Plus easy to talk to people and meet nice people, as it might be crowded and there will be people in and out, very informal atmosphere

B13 is (in their own words) not a chic restaurant, but a friendly bar where you can get filling food and have a good time with your friends.

It is located in a very centric location, next to Gran Via, one of Madrid's main streets. This contributes to its popularity, making it necessary to go early if you want to get a table.

The food is quite nice, ranging from different sandwiches (bacon, chorizo, squid, seitan, ...) or burgers to typical spanish starters as patatas bravas (fried potatoes with a spicy sauce) or tortilla de patatas (spanish omelette). The staff is very friendly and the atmosphere of the place is just great.

In my opinion. B13 is more than worth a visit if you have a craving for cheap, "junk" food and find yourself in Madrid.

My favorite Spanish style restaurant. Some of the best mock-meats you'll have, hands down the best potato omelet in the vegan world and the cheapest you can eat vegan in Madrid. Really, it's impressive the flavor and texture of its garlic unchicken, calamari, and some local specialties like croquetas. The bar itself is tiny and gets full easily, the staff is usually busy and is not very nice, and some dishes feature pre-made seitan or frozen onion rings (avoid them). But the sheer quality of the food deserves 5 stars. Oh, save room for dessert.

I have been going to B13 for a few of years now, and although I think there has been a slight change in the food lately( someone new in the kitchen?!) this Restaurant is worth flying to for my birthday every year!
I have had most of the dishes on the menu so I am going to give a detail review of the place.
My favourites are the Tapas: the Spanish Tortilla is a chunk of potatoes, brick looking like but light on the palate( I know, I know, a light brick, right? but you have to try it to see what I mean..); the Calamares made me question if I ordered some seafood by mistake, crispy crust, great flavour, the power of chickpeas for you.. I have had the Perrito Caliente on numerous occasion and it' s the healthiest by a mile, with fried onions and mustard. The puddings? well, cheesecakes are to die for, the caramel one is my favourite, but I also tried the strawberry one. Both have a puffy sponge and a creamy layer of queso ( I am still investigating what they use to make it..), the result is a light, guilt less dessert proving that milk isn't necessary to create great Patisserie...
As I read the comments, long wait for a table and rude waiters( I haven' met any in three years) can easily be overcome by Take Away option, which means you can have the best Vegan food while out in the sun or sitting on the balcony in your hotel room, at the end of a long day .
The only downside to my review is that I never take photos of my food, because as soon as it arrives on the table I take a bite to taste it and then it's covered in drool which makes it far form presentable ,LOLOL
The beers? Go for a Dark Estrella or a refreshing Mosto..
I can't fault the place, really, I would if I could! :D